Thread: Hi Guys - 2014 Disco 4 SDV6 - The common cracked inlet manifold issue!

Originally Posted by Rake

New to the forum so please bear with me.
Disappointing to learn I have a cracked inlet manifold at 114k - Plastic parts just don't go the distance!
Looses boost and needs replacing to avoid 'Restricted Performance' mode.
My mechanics suggest we do both at the same time since there is a lot of time involved dismantling and reassembling the covers.
Understand this issue is considered an expensive slug to the hip pocket.
Bit tentative about taking the disco for long runs, going bush, etc. in the future.
Comments appreciated.

Its very weird. My 2013 has 183,000 and no sign of the problem, and I have heard of cars with around 300,000 and no probs. Yet others can crack at around your klms.
Are you sure its not another problem, eg, intercooler pipe?

You'll get differing opinions here but I intend doing both sides next month simply 'cos I will be travelling on the mainland with a caravan in June/July/August and to have the problem occur then is too inconvenient.

Also, I'll be doing the oil filter/cooler "O" rings as well as oil separator "O" rings at rear of "V" at same time as it is a lot easier to do it whilst inlet manifold is off and only a short time to do. The "O" rings get hard over time and can leak oil.

You can go genuine manifolds (or non genuine at half the price,) however I think it is generally agreed that its best to go Genuine.

My LH manifold split at 160k. Opted for replacing both with genuine parts.
Replace the plastic coolant joint at the same time while it’s all apart.

Common failure for these machines, and probably more common in the older models than the new, as the part has gone through quite a few variations over the years.

I haven't heard of doing both being cheaper, as there aren't a lot of common parts to be removed - doing both is about twice the price of doing one.

Most of the time the LHS goes first, and if it does, the RHS will almost certainly fail in the future. If you plan to keep the car, I would just do both and sleep/drive easier, knowing you're good for quite a while. This is what I did.

And yep, I had the same 'I don't know if I can trust you now' moment with the car, but i look at it this way - the part failed for me when we were on holiday, towing a camper trailer. It was a pain, down on power etc etc, but it didn't stop us doing everything we wanted - still got there, camped, drove on the beach, and drove home again, still towing.

The D4 is an SDV6? So higher power rating than the TDV6. Has it been remapped or played with? One reason why I've never remapped my MY14 TDV6 is I don't want added boost to increase risk of failures like these.

For the record my MY14 D4 clicked over 300,000km last week. Both manifolds have been replaced, one at around 180,000km and the other went at about 210,000km. It clicked over 300,000km when out bush north of Southern Cross, WA, and ran like a dream all trip.

I am possibly doing the CSR next year, both mine will be done prior to the trip as a precaution along with a new alternator, compressor and air bags because all that is way cheaper than buying a new 4wd which will need cash spent on all the 4wding gear as well as the new car price only to get a 4wd that probably is no more reliable and more than likely not as good all round

Originally Posted by veebs

Common failure for these machines, and probably more common in the older models than the new, as the part has gone through quite a few variations over the years.

I haven't heard of doing both being cheaper, as there aren't a lot of common parts to be removed - doing both is about twice the price of doing one.

Most of the time the LHS goes first, and if it does, the RHS will almost certainly fail in the future. If you plan to keep the car, I would just do both and sleep/drive easier, knowing you're good for quite a while. This is what I did.

And yep, I had the same 'I don't know if I can trust you now' moment with the car, but i look at it this way - the part failed for me when we were on holiday, towing a camper trailer. It was a pain, down on power etc etc, but it didn't stop us doing everything we wanted - still got there, camped, drove on the beach, and drove home again, still towing.

RHS went first on mine. Bit the bullet and replaced both. 150k near enough.

*There is no rhyme or reason, some go some don't.
*I have plenty of customers with high mileage D4s, been tuned that havent had a cracked inlet manifold. 250K and plus.
*I have done plenty of both sdv6 and tdv6 with cracked manifolds.

*I generally say to customers do the side that's cracked as you arent going to save any money by doing both at the same time.
*If I do a drivers side manifold which is the most common, the passenger side may go in 10K, 100K down the track or it may never fail.
*I keep 6 drivers side manifolds in stock, I keep 1 passenger side in stock.

*Its more likely at some point in the manufacturing chain FoMoCo either screwed their existing supplier or went to another supplier to get a cheaper deal.
*Its just a typical FoMoCo part with average to poor quality control.

P.S I use genuine for no other reason than I have seen some no genuine ones that look like they are made out of the same plastic as a last model Defender dash, which in turn looks like its made out of the same plastic used in packaging for some expensive tool or equipment.

Originally Posted by discomatt69

I am possibly doing the CSR next year, both mine will be done prior to the trip as a precaution along with a new alternator, compressor and air bags because all that is way cheaper than buying a new 4wd which will need cash spent on all the 4wding gear as well as the new car price only to get a 4wd that probably is no more reliable and more than likely not as good all round

In addition to the airbags, do the shocks as well. It's a great trip but no so great right now.